How plants survive the way they do
February is not a gardening month. I could really do without it; it fills the period between January and March and that's it!
However, it continues to be part of Mother Nature's seasonal calendar even though it is one of the most undesirable ones from the point of view of weather related problems. Little growth is seen at this time of year, yet wind and salt damage can be serious to plant structure, so this is a good time to discuss how plants survive the way they do!
Fertilisation can be a controversial subject, to the point it is very rarely discussed as part of the maintenance programme. Yet in tandem with several other techniques, it is a process that is required for good growth and survival!
Several very important processes in plant development include:
Absorption: The intake of water and mineral elements by the root system.
Photosynthesis: In simple terms, the process by which the energy of sunlight is used by a green plant to keep it growing.
Respiration: The combination of oxygen with various food substances synthesised by the plant, especially sugars, whereby energy is produced.
Transpiration: Loss of water from the plant mainly from the leaves.
Translocation: The movement of materials within the plant.
Storage: Storage of reserve products in various organs and tissues.
For the normal functioning of these processes, an adequate amount of water must be available for the plant to maintain plant cells in a turgid state. Seasons have an impact on plant growth especially in areas which have large swings in temperature; Bermuda has in my opinion only two seasons, hot and not so hot! Rainfall in 2011 was lower than normal and unevenly spread out through the year which impacted growth and indeed planting.
The plant environment is important in numerous ways with the elements of rain, sunshine and wind including salt spray having a major impact on plant growth. Landscaping is made more difficult by our soil conditions; with areas almost devoid of soil depth whilst other soils are almost pure sand and numerous “combinations” between. The importance of planting in a good size hole with “soil” cannot be stressed enough if the plant is to attain its potential in growth and flowering.
To support growth, nutrition is important, but nutritional problems must be considered in relation to the conditions in which the plant lives, and not necessarily in the amount of fertiliser given or found in the soil. For example, fertiliser applications given during high temperatures can be injurious to growth, especially if soil has a soil moisture deficit.
Fertiliser (mineral nutrients) comprises numerous elements required for plant growth with some elements being required in larger quantities, these are referred to as essential or “major” elements, whilst those required in lesser amounts are referred to as minor or trace elements. The major elements are nitrogen, phosphorous, potassium, calcium, magnesium and sulphur. Trace Elements are manganese, iron, boron, copper, zinc, chlorine and molybdenum.
The function of these elements is useful in understanding the effects produced by deficiencies of any one of them:
Nitrogen: Required in relatively large amounts for all growth processes; if deficient, leaves turn pale green and plants can remain stunted.
Phosphorous: Deficiency can result in greatly reduced growth; it is important in the germination process of seed and the ripening process of fruit and seeds.
Potassium: Deficiency effects seen in older tissue and progress toward growing point where in severe cases die back of growing point can occur.
Calcium: Actively concerned with growing point, deficiency shows at this area first. It is also important in root development.
Magnesium: With deficiency one of the first symptoms seen is chlorosis on older leaves progressing to younger leaves.
Sulphur: Deficiency of a similar characteristic to nitrogen deficiency.
Trace element deficiencies are difficult to determine on a casual basis; if general fertilisation, be it granular or liquid fails to resolve the problem, take a sample to the Department of Environmental Protection for an analysis.
To supplement fertiliser applications consider using your own organic matter which can be both useful for the garden and a money saving exercise simply by keeping it on the property and not trucked away at a cost to you.
Do not compost unhealthy material burn it but all horticultural debris from the garden can be used; chip branches and larger items and mix with foliage and organic kitchen waste. Turn the pile regularly especially in summer to encourage breakdown of material by the heat generated in the 'pile. When the 'mix' breaks down to a fine texture turn into the beds and create a good humus material which will greatly assist in good growth. To enhance the mix further, incorporate well rotted horse or cow manure and watch the results of your labours blossom forth!